Apparatus for cementing oil wells



Patented May 14, 1929.

DONALD D. BURCH, OF OKMULG-EE, OKLAHOMA.

APPARATUS FOR CEMENIING OIL WELLS.

Application filed June 21,

This invention relates to apparatus for cementing oil wells and moreparticularly to an improvement of the oil well cementing apparatusdisclosed in my prior patent, No.

1,603,447, granted October 19, 1926, for casing shoes.

An important object of the invention is to so rearrange the structuredisclosed in this prior patent that the plug is much more readilydrilled out after the cementing operation has been completed and is muchmore readily installed for service.

A further object of the invention is to produce a device of thischaracter so constructed that the elements thereof may be formed andseparately shaped and the assembly thereof completed by the purchaser,thus materially reducing the cost of shipment and the difiicuh ties oftransportation. In this connection, it is pointed out that oil wells areoften located at almost inaccessible points and the transportation ofheavy materials is always a serious problem.

These and other objects I attain by the construction shown in theaccompanying drawings, wherein for the purpose of illustration .is showna preferred embodiment of my invention and wherein 2- I igure 1 is avertical sectional view through apparatus for cementing wellsconstructed in accordance with my invention, a plug being disclosed asseated upon the upper end of the control element to close the upper endsof the conduits thereof;

Figure 2 is a horizontal sectional view therethrough.

In accordance with the present invention, I provide a casing shoe 10,the interior wall of which is circumierentially recessed, as at 11, toprovide shoulders or seats preventing movement of a cast concrete plug12, which may be formed therein. In combination wlth this casing shoe, Iprovide a control element, whichcomprises a central casing 13 having incommunication with the upper end there-. of a conduit or conduits 14,the ends of which are downwardly directed and extend belowthe lowerlevel of the casing. Communicating with the bottom of the casing areconduits 15, the ends of-which are upwardlyduected and extend above thetop of the cas.1ng.'- Interiorly, the casing is provided w th a valveseat 16 having cooperating therewith a check ball or check valve of anysuitable character, designated at 17 and seating downwardl In the use ofthe apparatus, as descri ed,

1927'. Serial No. 200,424.

the control element is placed in the casing shoe in alignment with therecess 11 and ce- {nent poured thereabout to form the plug 12 in whlchthe control element is completely embedded, with the exception of thefact that the ends of the conduits l4 and 15 open tively.

In cementing a well, this device is attached to the lower end of thecasing and when the casing is at the proper position, pump pressure isapplied to drive the cement through the control element where, in itspassage, it lifts the check ball 17, passes the same and discharges fromthe lower end of the casing shoe through the conduits 14. After thecement has been completely forced through the control element which, maybe determined by the fact that a plug 18 following the same seats uponthe upper end of the control ele ment and closes the upper ends of thecon-i duits 15, the pump pressure is relieved and any tendency of thecement to return to the interior of the casing through the controlelement will be prevented, by reason of the fact that the check 17 willseat and will be held seated by the pressure of the incoming cement.

When the cement has fully set, the plug 18 which, if desired, may be ofcement and the plug 12 are drilled from the shoe in the usual manner.The control element may be formed I from tin or galvanzed iron of lightgauge and will not materially interfere with the drilling operation, asis the case with a heavy metallic body, suchwas described in my priorpatent above mentioned. While I have above referred to the plug 12 asbeing constructed of concrete, it will readily be ,pnderstood that thisplug may be constructed of any castable material which is readilydrilled from the shoe without dama e to the drill. Among such substancesmig t be mentioned in addition to the concrete previously mentioned woodor paper pulp and plaster of Paris. All of such substances, however,should be ma terial which can be readily pulverized.

Since the construction hereinbefore set forth is capable of a certainrange of change and modification without mater ally departing from thespirit of the invention, I do not .limit myself to suchspecificstrueture except as hereinafter claim I claim:- 1. Incomblnatio'n, a. casmg shoe having 1ts interior wall recessed, a castconcrete plug through the bottom and top thereof respec- I within theshoe and having: portions extending into said recess whereby the plu isheld against movement with relation to t e shoe; a control element castwithin the plug having means permitting fluids to flow through the plugfrom the upper to the lower end thereof, but preventing return flow ofsuchflu1ds,' the control element comprising acas ing, a conduitcommunicating with the upper end of the casing and extendin downwardlythrough the bottom of the p ug, 'a second conduit communicating with thebottom of the casin and extending upwardly through end thereof, aplurality of conduits arranged eccentrically to the chamber and extendmbetween said valve seat and the up or on of the plugformingvcommunications etween the interior of said chamber and theinterior of thecasing shoe above the plug, other conduits arrangedeccentrically to the chamber intermediate the other conduits andextending between the lower end of the plug and the upper end of thechamber forming communication therebetween, a ball valve in the chamberada ted to cooperate with the valve seat; said bal valve permittingfluids to flow from the up er end of the plug throu h the chamber anthrough the lower end t ereof but being seated by the return flow offluid from the bottom of the plug to prevent the fluid from 'pass'through the plug. In testimony v vffie signature.

' DONALD D. BURCH,

reof I hereunto afiix my 40

